Amid growing concern about the impact of smoking on health and productivity, employers have sharply stepped up restrictions on when and where employes may smoke at work, according to a study published yesterday.

Fifty-four percent of 623 companies surveyed this year have adopted smoking policies, compared with 36 percent in a similar study in 1986 -- a 50 percent increase that took some experts by surprise. These policies range from prohibiting smoking in open work areas to outright bans on smoking in company buildings.

"No longer is the primary question facing most employers whether smoking should or should not be restricted," the report said. "Increasingly the core question is: How should smoking be restricted in the workplace?"

The study released yesterday was carried out by the Bureau of National Affairs, a Washington research and publishing group, and the American Society of Personnel Administration, a trade group for 36,000 personnel executives around the country.

Its release comes as governments are showing a growing willingness to restrict smoking in work places. The General Services Administration adopted rules earlier this year limiting smoking to designated areas within 6,800 federal buildings, while 14 states and 200 localities have passed some kind of smoking control laws that apply to private business, according to yesterday's study.

Now, it appears, the private sector is moving to limit smoking at work sites.

While only 12 percent of the companies with smoking policies have adopted an outright ban on smoking in all company buildings, 51 percent of companies with policies have prohibited smoking in open work areas -- up from 41 percent in 1986. That's a fairly dramatic sign of the new restrictive attitude by employers, according to study organizers.

Jeff Day, a BNA researcher who helped coordinate the study, said one of the major reasons for the increase in smoking restrictions appeared to be growing concern among employers about the health of nonsmokers.

Part of the reason may be the Surgeon General's report last year linking low doses of tobacco smoke to disease in nonsmokers as well as smokers, Day said.

Almost three-quarters of the companies that have adopted a smoking policy said they were prompted by concern for employe health and comfort. Fifty four percent mentioned employe complaints.

According to the study, several local employers have already joined the national trend to smoking restrictions.

They range from Fusion Systems Corp. of Rockville, which limits smoking to certain smoking rooms, to the Arlington and Fairfax fire and police departments, which ban smoking by new employes.

Jane Long, a vice president of Technology Applications Inc., an Alexandria high-tech firm with 450 area employes, said her company recently informed workers that smoking would be banned in all company buildings as of March 1 next year.

"The reason is we're basically concerned about the health and well-being and productivity of our employes," she said.

"It's not only concern for the people who smoke, but also for the ... people who don't."

Brennan Moran, assistant to the president of the Tobacco Institute, the industry's lobbying group, criticized such arrangements.

"Both the smoker and the nonsmoker need to be reasonably accommodated," she said.

"A total smoking ban is not a reasonable accommodation."

She also expressed surprise over the survey's findings, saying that the institute's experience is that smoking restrictions are not increasing as rapidly as the study indicates.